Re: table row "checksum"

"Geoff Muldoon" <geoff.muldoon_at_trap.gmail.com> wrote in message news:MPG.1e28a0d41114c791989741_at_news.readfreenews.net...
> downwithspammersfamily_at_attbi.net says...
> >
> > "Geoff Muldoon" <geoff.muldoon_at_trap.gmail.com> wrote in message
> > >
> > > Seeking advice as to the best method of generating a "table row
checksum".
> > >
> > you can use the built in Oracle functionality to generate a hash. (See
Tom
> > Kyte's latest book). I don't have it in front of me but look at the
> > documentation for the md4,5 or sh something or other check sums (hash)
>
> Have looked at DBMS_OBFUSCATION_TOOLKIT.MD5 but am not certain it will
> always return
> a) distinctly unique values
> and
> b) matching values when populated tables are subsequently migrated across
> servers (dev -> prod)
>
> Anyone able to advise?
>
> TIA
>
> Geoff M

Yes, look at the
http://download-west.oracle.com/docs/cd/B19306_01/appdev.102/b14258/d_crypto.htm#sthref1559 and use the sha-1 algorithium the secure hash 1. Given the same inputs you will get the same hash. It is highly unlikely that you will get the same hash for different inputs. Yes, it is possible, but the odds are very very very low. (out of a 160 bit message the odds are better you will win the Powerball lottery). I think this is the recommended hash algorithium for what you propose.
Jim Received on Thu Jan 05 2006 - 23:08:57 CST